Safety deposit box lock



2 Sheets-Sheet 1 IN VEN TORS ATTORNEYS Sept. 17, 1963 R. T. ELLIS ErAL SAFETY DEPOSIT Box Locx Filed Aug. 1, 1960 FIG.|.

FIG.3.

ROY T. ELLS BY STEPHEN A. DENMAN Sept. 17, 1963 R. T. ELLIS ETAL 3,103,80@r

SAFETY DEPOSIT BOX LOCK Filed Aug. 1. 1960 2 Sheets-Sheet 2 ROY T. ELLIS BY STEPHEN ADENMAN,

ATTORNEYS United States Patent O 3,l03,806 SAFETY DEPOSIT BOX LOCK Roy T. Ellis, Baryton, and Stephen A. Denman, Piqua, hio; said Denman assigner to said Ellis Fiied Aug. l, 1960, Ser. No. 46,447 24 Claims. (Cl. 'l0- 339) The present invention relates to a safe deposit box lock. The lock, and many features of it, are capable of more general use but it has particular applicability to safe deposit boxes.

In general, the lock consists of a housing containing a movable bolt that can be projected for locking and' withdrawn for unlocking purposes. Two key noses are provided for the lock. Conventionalily, one key nose is for the guard key, ,and the other key nose is for the customers key. The lock has a set of primary tumblers that extend adjacent to each nose, to be operated by keys therein, directly or indirectly. At least some of these primary tumblers must lbe displaced by keying in both key noses. These tumblers have no iixed pivot, so that when they tare displaced by one key, they rock about the other key nose, or about parts associated therewith. This absence of fixed pivots for these tumblers adds to the security of the lock, by increasing the ditliculty of detection.

The present lock may be built to operate with the familiar sequence of -guard key unlock, customers key unlock, and retraction of the bolt by the customers key. Alternately, it may be arranged to be operated by customers key operation' or guard key operation in the guard key nose followed by customers key operation in the customers key nose. Similarly, it maybe arranged to be operated by three or more keys in which event there would be two or more keys operated through the guard key nose and another key operated through the customers key nose.

The principal purpose of this lock lis to prevent its being picked. One of the principal features of `the lock is that it has means to prevent detection of they arrangements of the tumbler slots by sound detection methods. With current locks it is possible for unauthorized persons to obtain a full set of tumblers with all slot positions for any particular make of lock. Individual locks of such make differ only in the arrangements or combi-nations of relatively small number of tumblers. Therefore, with appropriate miniaturized instruments, an unauthorized person may determine resonance characteristics of each tumble-r of the relatively small number of tumblers of a particular make `of safe `deposit box lock tdiat differ from each other in slot arrangement. Then with the characteristics charted, he may at his leisure and with appropriate miniature instruments, detect the sound 'characteristics of each tumbler of a given safe box lock, and thereby readily learn the slot arrangements of the tumblers in that particular lock, so that he can easily make a key or keys therefor.

Thus va primary object of this invention is to provide means to prevent detection of the tumbler arrangement in a lock by sound detection devices oper-atingr through the resonance characteristics of the tumblers. A further objectl is to provide a lock having tumblers, the sound ice 2 the resonance qualities of which do not indicate the slot arrangements of the tumblers.

A further object of the invention is to provide safe deposit locks in which the guard key may not readily be detected. In conventional safe deposit box locks the guard key can be readily detected by any one possessing a custoniers key @and a right to the opening of any box controlled by la single 4guard key.

A further object of the invention is to prevent picking or detection of key requirements by probing of the tumbler slots through the key nose. Barriers are provided to interfere with such probing.

Another object of the invention is to prevent high keying Fby the use `of a customers key with high rises on it. To avoid this, one or more tumblers have slots above center so that it or they `may be lowered by the guard kex instead of providing only tumblers that are operated by lthe conventional lifting thereof.

In the drawings:

FIGURE 1 is a front elevation of a lock embodying the present invention, with the cover removed, and parts broken awlay;

FiGURE 2 is a horizontal section on the line 2-2 of FIGURE l;

FIGURE 3 is a vertical transverse section on the line 3 3 of FIGURE 1;

FIGURE 4 is a vertical longitudinal section on the line lll-4 of FIGURE 2;

FIGURE 5 is la horizontal section on the line 5 5 oi FGURE 1; v l

FIGURE 6 is an elevation' of a typical primary turnbler; and

FiGURE 7 is an elevation of a typical secondary tumbler.

This lock includes a casing 20 having .a cover 21 providing two key nose cylinders 22 and 23. The cover cylinder 22 rotatably receives the key nose 24 while the cover cylinder 23 rotatably receives the key nose 25. The key nose 24 has 'a key slot 26 and the key nose 25 has a key slot 27. Preferably the key slots are blind, ie., do not penetrate the back wlall of the lock housing 20.

One end wall of the housing 2t) has a slot 3d to receive the projecting end of a bolt 31. As illustrated, this bolt slides Within the housing Z0' and is guided by a pin 32 on the casing 2idl operating within |a slot 33 in the bolt shank, anda pin 34 operating within a notch-like slot 3S on the bolt shank. Also `a lateral `guard in the form of a ridge 35 extending out from the side wall of the housing 20 gives proper lateral support to the bolt 31.

'Ihe .bolt is actuated by a bolt operating cam' 39 mounted upon the -custorners key nose 24 to rotate therewith. The cam 39 operates in a slot in the shank of the bolt which has :an arcuate portion 40 as indicated and an actuating portion comprising a reti-acting cam edge 41 and a return carn edge 42. The return' cam edge 42 merges into the arcuate edge 40. By this arrangement the `bolt actuating cam 39 rotates freely until it engages the `bolt-retracting edge 4l. Further clockwise movement after such engagement causes the bolt 31 to be withdrawn. When the key nose Z4 is moved in the opposite direction or Icounter-clockwise from the unlocked position, the opposite side of the cam engages the edge 42 and moves the bolt `fully out, after which time the cam moves freely within the space provided by the arcuate edge 40. When the cam is in its locked position, the nose thereof engages back of the lower part of the arcuate edge 40 and prevents retraction of the bolt 31.

The regulation of the movement of the lbolt is mainly under the control of a group of primary tumblers. The bolt 31 has on it a lug 4S wit-h a concave end 46. The lug 45 cooperates with a series of primary tumblers 50. Eight of these are illustrated and are individually designated 50a through 50h. Conventionally, different locks comprise different :combinations of eight, more or less, tumblers, such as these.

To a large extent these primary tumblers may be identical, and in general they all have the shape illustrated in FIGURE 6. Each primary tumbler includes a igenerally horizontal shank 51 having an actuating edge 52 overlying the customers key nose 24, a notched head 53 extending downwardly from the left end of the shank 51, and a guide projection 54. The guide projection has a slot 55 engaging over a pin 56 secured tothe wall of the housing 20.

The right end of the primary tumbler shank 51 in the illustrated view extends over and has an actuating edge 57 overlying the guard key nose 25, in position wherein it may be engaged by a key inserted into the guard key nose. For some purposes some or all of the primary tumblers may be extended beyond the gua-rd key nose and provided with an arcuate notch 58 and a ledge 59. As will appear, these last two features may be eliminated under certain circumstances.

The primary tumblers S0, where they overlie the customers key nose 24, may, when the key is withdrawn, rest upon the key nose, or they may preferably rest upon secondary tumblers as will appear. ln the illustrated form there is a secondary tumbler 62 for each primary tumbler, these tumblers being indicated individually as 62a through 62h. 'I'hey are all rotatably mounted ppon a secondary tumbler pivot pin 63 projecting trom the housing 20. From this pivot pin 63 the secondary tumblers 62 extend leftwardly in the drawings, to overlie and rest at times upon the customers key nose 24 and to underlie and receive the actuating edges 52 on t-he undersides of the primary tumblers. The secondary tumblers may have forwardly extending actuating ends 65 shaped to be operated by the key as will appear. When so operated, the secondary tumblers are pivoted vclockwise about their pivots 63 and elevates the portions of the primary tumblers directly above them in amounts determined by the shape of the key. Preferably, at least one of the secondary tumblers has its key-receiving portion 65a serrated, as illustrated, to produce clicking sounds `during keying, thereby confusing detection of the lock by sound-reading of the tumblers, and to provide audible means for alerting a guard to tampering with locks.

The heads 53 of all of the primary tumblers extend downwardly at the lett side of a barrier 66 formed on the housing, that is to the left side of the customers key nose in the drawings. The barrier 66 interposed between the key nose 24 and the depending portion 53 of each of the tumblers prevents probes ffrom being directed from the key nose to the portions 53 of the tumblers to detect location of the slots.

The head portions 53 of the primary tumblers extend along adjacent the lug 45 of the bolt 31. The left edge 67 of each primary tumbler is provided with a main slot 68, that is located in one of eight (more or less) positions along that edge. Different tumblers have the slots 68 at different elevations. Dummy slots 69 and 69' may also be provided. As will be understood, when all of the primary tumblers are properly elevated with respect to the lug 45 on the bolt 31, the bolt may be moved to the right, the lug entering all of the several slots 68. However, if any one slot 68 is misaligned with the lug, the lug may not be moved to the right and the bolt may not be retracted.

It may be noticed that the right end of the lug 45 is concave. This assists in preventing the lug from moving to the right against a not quite properly aligned slot.

It also -will be seen that the heads 53 of the primary tumblers extend almost to the bottom wall of the housing 2t). These parts are so proportioned that if someone saws olf the ends of the tumblers by using a saw inserted through :the keyhole, these heads 53 will fall only a short distance that is not enongh to move them out of the way ofthe lug 45 of the bolt. Therefore, the bolt will remain locked.

An important feature of the present invention is that holes or the like, such as the hole 70, are made in the tumblers; these holes can readily be located at different points in the tumblers. They prevent otherwise identical tumblers from having identical resonance characteristics. Thus in the present lock, with eight tumblers that dilfer in slot location, an unauthorized person might be able to develop patterns of resonance for each of the eight tumblers. Each resonance pattern would represent, therefore, -a tumbler having a particular slot position. But with the resonance tuning holes 70 variably arranged on otherwise identical tumblers, the resonance characteristics are so modiiied detection by resonance cannot `be performed.

Furthermore, the reaction edges of the primary tumblers over the key noses may be varied. The edge portions 52 and 57 may be moved by cutting back certain of the tumblers or building up the tumblers at these points thereby changing the positioning of the tumblers with respect to the key, and at the same time changing the resonance of the tumblers. These changes can be made without changing the position of .the slots, and will change the key. The two foregoing actuating edge changes provide a lange ynumber of additional combinations possible from a basic set of tumblers that are essentially identical.

The tumblers are all urged downwardly by spring action. To this end, a gang leaf spring 76 has one end secured at 77 tothe end wall of the housing 20. The free end of the spring 76 maybe separated into a plurality of spring leaves 78a through 78h corresponding in number to the primary tumblers. The leaves 78 overlie the primary tumblers somewhat to the left of the guard key nose 23 and yieldably and resiliently urge these tumblers downwardly. This holds the tumblers against the guard key nose or against the key; and it also holds them against the secondary tumblers and urges those tumblers downwardly against the customers key nose. These springs return the tumblers to their lower positions when the box is locked. Both the springs and the tumblers may be guided by a tumbler guide 80 projecting from the housing beside the tumblers. Another tumbler guide 81 projects from the housing 20 adjacent the slot projections 54 of the tumblers and acts `as a guide.

If three (or more) key operation is desired, an additional lever assembly is employed. This is illustrated at the right end of the Ihousing adjacent the guard key nose. This lever assembly comprises front and back levers 86 and 87 rockably mounted on a pivot pin 88 projecting from the back wall of the housing 20, with a spacer sleeve 89 between the lower ends of the levers to maintain them in proper spaced relationship. At their upper ends the two levers 86 and 87 support a primary tumblers fulcrum pin 90. The pin 90 also supports a trip lever 92 of bell-crank shape. This lever overlies the guard key nose 25 forwardly of the primary tumblers and has a generally rectangular notch 93 above this nose. Its depending end can rest against a spring flug 95 projecting transversely from the pivot pin support lever. A leaf spring 96 is disposed about the sleeve 89 so that it engages the bottom wall of the housing at one end and engages the lug 95 at the other end, normally resiliently to urge the pivot supporting levers 86 and 87 clockwise and the pin 90 to the right in the drawings.

This action is, however, restrained when the notch 58 of any primary tumbler is engaged over the pin 90.

To prevent the use of a 'high key as a third key to operate the special primary tumblers that are designed to be low rise tumblers, one or more of the latter can be provided with an extended lug 99 that will interfere with action of the corresponding leaf or leaves of the spring 78. Such lug will engage the leaf much closer to its bend, and thereafter fuither lifting of the end of the tumbler will be against an extra resistance. If a high keying is attempted, the sudden development of this extra resistance indicates that the tumbler has reached engagement with the top of the housing, Whereas actually it is not as high as its lock-opening position.

Operation The operation of this lock will first be described as a three or more keying operation. In this case, certain of the primary tumblers 50, but not all of them, are pro'- vided with the extensions to form the notch 58 and the ledges 59. These particular tumblers may have, and should have, different heights of the actuating edges 57, or of the ledges 59, so that it will require different and varying levers of the key edge to elevate them to free the notches 58 from the pin 90. All of such special primary tumblers will be freed from the pin 99 when they are elevated appropriate amounts by the diiferently cut portions of a key. This key can be either the guard key, the customers key, or a third (or more) key. Considering that it will be a third key, the operation will be that the person holding the third key will perform the iirst operation, by inserting that key into the guard key slot and turning it approximately 90 so that it will elevate the right ends of all of lthe special primary tumblers that have notches 58 until they are free of the pin 90, whereupon the spring 96 will quickly displace the pin 90 to the rightward until the levers 86 and 87 engage the right end of the housing. This may produce an audible clic which can advise a holder of such key of any unauthorized performance of this function. In this released position of the pin 90; it will be disposed under the ledges 59i on the special primary tumblers having such ledges. V Y

The second function to be performed (the rst if the foregoing features are omitted) is the guard key operation. The guard key is inserted into the guard key nose 25 'and turned approximately 90. key has edge formations to elevate the right ends of the remaining previously unmoved primary tumblers Sil, or as many of them as it is desired to move. They are moved to diiierent elevations by the different parts of the key. Tlhis guard key action rocks these primary tumblers 50 about their engagement with the secondary tumblers, and in effect lowers the heads l53 of these tumblers, and the slots 68 thereof. This does not, in any case, dispose all tumblers `50a-h, into unlocking position. The guard key is normally then left in the lock. In this action, a forward rise on the guard key slips into the notch 93 of the trip lever 92, for a purpose to be described.

The next operation is to insertl the customers key into the nose 24 and turn -it approximately 105. This will cause a series of audible clicks as the key engages the serrations 65a on the secondary tumbler or tumblers so serrated. The customers key is designed to elevate the secondary tumblers 62a through 62h different `amounts depending upon the shape of the edge of the customers key. Consequently, the left ends of these secondary tumblers 62 are raised different amounts, and they correspondingly act upon the primary tumblers 56 to raise the primary tumbler heads 53 different amounts. Since the slots 68 in the heads of the primary tumblers are located at different positions along these lheads, which means that they are at different elevations, the elect of the different portions of the customers key edge on the primary tumblers after the prior keying, is to align all of the slots 68 opposite the lug 45 and enable the lug 45 to move to the right into the combined slots 68. Then the nal movement of the customers key may be made to cause the cam 39 to engage the edge 41 on the bolt to move the bolt to the right, unlocking the lock. rl`he guard key may be removed at this point, if desired.

'It is preferable that the notches 68 be widened as they extend into or rightwardly ofthe tumblers. If they have this shape, then if the guard key is removed while the lock is in its unlocked position with the bolt retracted, the right ends of the primary tumblers will be forced downwardly by the springs 7-8 to their initial positions. This dropping of the right ends of the tumblers when the guard key is removed will prevent a reading of the guard key for all of the boxes in the group, which may otherwise be done in locks wherein closely itting slots hold 'the tumblers elevated after the guard key -is Withdrawn. It -is easy to determine the elevations of the surfaces 57 on the right ends of the tumblers of con-ventional locks while they are held in their elevated positions with the guard key withdrawn. A guard key can be fashioned in a matter of only a few seconds with conventional safe deposit box locks, by removing the guard key when the customers key is in its unlocked position and then inserting an appropriate blank into the guard key nose. In 4the present flock, the sizes of the right end of the lugs 46 and the opening or left end of the slots 68 should be close with only -a limited tolerance, since this makes the action more accurate and makes the lock more difficult to pick. =But the necessary lost mdtion may be provided by tapering the lug to narrow it to the left of the entrance end 46, or by widening the slots 68 to the right of their entrance ends.

When it is desired to relock the box, the customers key is usually iirst turned counterclockwise to its initial position, and is Withdrawn. The irst of this action causes the cam 39 to move counterclockwise. Its left edge engages the ledge 42 during the rst'of the angular motion and leaves that ledge when the bolt is completely into its locked position and lug 45' is withdrawn from notches 68. Thereupon further angular movement of the cam 39 does not actuate the bolt. In the meanwhile, the withdrawal of the lug 4S from the primary tumbler notches 68 with the movement of the bolt enables the spring 76 to cause the primary and secondary tumblers to move downwardly to their initial positions.

The inal locking action may consist of removing theL guard key by turning it counterclockwise until a special rise on the key engages the left edge of the notch 93` of the trip lever 92. Thereupon the trip lever and the pin are moved counterclockwise. This moves the pin 90 out from the ledges 59 on the right ends of the selected ones of the primary tumblers. Thereupon these selected tumblers, along with all other primary tumblers, fall again into their starting positions.

'The present'lock not `only overcomes possibilities of detecting the characteristics of the guard key for reasons already noted 4but also prevents detecting of the customers key by means that can detect characteristics of existing locks.

In the iirst place, the use of the secondary cam or tumblers interposed -between the key nose and the primary tumblers makes it more diiiicult to determine the designs of the primary tumblers, either by mechanical devices such as picks, yor by sound detector devices. This is particularly true where the secondary tumblers vary in thickness or in length. There is, therefore, an advantage in having two sets of tumblers. Also the barrier 66 interferes with the insertion of probes into the customers key nose to determine the positions of the slots 68. Examination of the drawings .Will show that an angular probe cannot be directed from the nose to the slots 68. Y

It is a further advantage to have one yor more of .the primary tumblers not to be displaced by the customers key. It can 4be observed that the eilect of lifting the right ends of the primary tumblers by the guard key is to lower the head 67 and the slots 68. If the customers key does not act on one of the tumblers, its slot can be located above the lug 4S rather than below it, when the lock is locked. This prevents a high key operation in a customers key slot,in which the slots 68 are located by a high key or a pick that raises all of the tumblers and then lets them down until the notches 68 come against the lug.

One of the most important features of the present invention is the anti-resonance feature here exemplified by the presence of the holes 70 in the primary tumblers. With conventional safe deposit -box locks there are usually a denite number, such as iive to eight tumblers containing the slots corresponding to the slots 63. There may be more than one set of tumblers. All of the various different locks are developed from combinations of these live to eight, more or less, tumblers. Consequently, if someone obtains 'one or two locks of a particular make and style he can obtain a full set of tumblers having the full range of slot positions. Conventional tumblers which are identical have closely similar resonance characteristics.

Therefore, one having a complete set of tumblers may, with appropriate instruments determine the sound picture or oscillogram characteristic of each tumbler with a particular slot position. Having made this preliminary determination, the lock picker has only to use instruments that permit him to develop the resonance characteristics of each of the tumblers chosen for the particular lock of that make that he wishes to open, and to compare each with pictures of the resonance characteristics of the known tumblers. When a record of the sound characteristics of a hidden tumbler ris found to be nearest to one of the predetermined oscillograph patterns, the operator knows the slot arrangement of that tumbler. With miniature resonance detecting and recording instruments, with the later use of an oscilloscope, this operation can be performed with no difficulty. i

With the present lock, the iirst thing to note is that the customers key slot opens only to the secondary tumblers. While the lock can be built without such tumblers, these secondary tumblers provide the advantage that they are the only parts available to instruments through the key slot. Merely to determine the resonance characteristics of the secondary tumblers does not determine the arrangements of the slots in the primary tumblers. And even if the secondary tumblers are not individually characterized themselves, but are all identical, they still can prevent determination of the resonance qualities or patterns of the inaccessible primary tumblers above them.

Additionally, the holes 70, or other similar means, are used to confuse the resonance patterns of individual tumblers. Thus, a given set of stampings may be used for all tumblers and the variations of the slots 68 made as desired. If the holes 70 are used in different positions, numbers or sizes as can be readily done, the resonance characteristics do not follow fixed patterns, and it becomes impossible -to determine the nature of the key by simple determinations of resonance qualities through the key slot.

The holes 70 are designed to be illustrative of what may be done to change the resonance qualities of these parts. Other means may -be used, such as diiferent tumbler materials, or the addition of sound changing or deadening elements to the tumblers. Hence, while the simplicity of a lock made of a relatively small number of tumblers having basically the same shape is preserved, nevertheless the difference of resonance qualities is obtainable, and this form of detection is prevented.

It thus may be seen that this lock is relatively simple in design and construction but is very diiiicult if not impossible to open without the proper operation of the keys. Also the key design may not be determined from the key slots in contrast to most existing locks of this type. The lock also provides three-or-more key operations as desired or two-key operation if that is preferred.

Various modifications within the scope of the claims to follow may be made without departing from the inventions herein set forth and equivalents thereof. It must also be understood that features above-described may be adapted to other types of locks. This is particularly` true of the resonance characteristics feature, which is adaptable to any type of tumbler or cylinder lock wherein diierent locks are provided from a relatively small nurnber of different tumbler-like elements, by employing the elements in different combinations and arrangements. Detection of the tumbler situations can be prevented by so altering resonance characteristics of the individual elements of any one type.

Three-or-more key operation can be changed to twokey operation by eliminating all tumblers with slots 58, and the associated parts. Other changes and adaptations of the inventions hereof should be apparent.

What is claimed is:

l. ln a lock: la housing; a key nose having a key slot therein; la plurality of tumbler-like elements in the housing adapted to be actuated by a key in the slot; and movable means interposed between the tumbler-like elements and the key nose to render difficult the introduction of a rod-like probe lengthwise of the key slot to engage the tumbler-like elements and to transmit blows to such elements to and in detecting sound characteristics of the tumbler-like elements, said movable means being adapted to hold the elements away from the key nose, but to transmit key-movements to the tumbler-like elements.

2. In a lock: a housing, a plurality of tumblers mov- 'ably mounted in the housing; a bolt movable in the housing; each of the tumblers having a head adjacent the bolt, the various tumblers having differently-placed slots in their respective heads; a lug on the bolt movable into the slots when they are aligned to permit the bolt to move to unlocking position; a first and a second key nose; each of `the Itumble-rs having a shank extending across yboth noses; fthe heads being to one side of both key noses; so that displacing the tumblers from the iirst nose lowers the slots and displacing the tumblers fnom the second nose raises the slots.

3. The lock of claim 2, wherein there are keys for -both noses, and the key for the second nose has `means to leave -at least one tumbler in its lowered position into which it Was placed by the other key.

4. The lock of claim 2, wherein at least one ofthe tumblers has a recess and a ledge beyond the first nose; a pin normally engageable in the recess when the lock is locked, means supporting the pin for movement to a position to support the ledge when the tumbler is raised to free the pin from the recess; whereby that tumbler may be positioned individually.

5. The lock of claim 4, wherein the supporting means hasappariatus operated by movement of a key to locking positron to return the pin to its recess-engaging position.

6. In a lock: a housing, la locking element movably mounted in lthe housing for displacement to lock and unlock positions; and key-operable mechanism to control movements of the locking element from lock :to unlock position; the mechanism including a plurality of primary ltumblers in" the housing movable from released, lock position to unlock position; mowably interengageable elements on the locking element and on the tumblers, those on the different tumblers being differently spaced so as to require different amounts of movement from released, -lock posiytion yfor dilferent tumblers to enable the element to move to unlocked position; a key nose, the tumblers extending acnoss the key nose to be displaced by 'operation of a key therein; a pin, means movably mounting the pin for displacement :adjacent the tumblers and the key nose, at least some of the tumblers having each a ledge under which the pin may move when the tumblers areshifted by a key, the pin then maintaining the tumblers thus displaced; and a trip lever spaced from the tumblers alon g the key nose, to be actu-ated by the key, the trip lever having yan edge en- -gageable by the key to move the lever and the pin t tumblerJreleasin g position 7. The lock of claim 6, wherein the trip lever is rockably mounted upon the pin.

8. The lock of claim 6, wherein the pin mounting means is spring urged toward position under the ledges, the tumblers, having means to hold the pin away from such position, which means are rendered ineffective by the key.

9. ln a lock: la housing, a locking element movalbly mounted in the housing for displacement to Ilock and unlock positions; and key-operable mechanism to control movement-s of the locking element from lock to unlock position; the mechanism including a plurality of primary tumblers in the housing movable from released, lock position to unlock position; movably interengageable elements on the locking 'clement and on the tumblers, those on the tuniblers being differently spaced so las toI require ditte-rent amounts of movement from released, lock position for different tumblers to enable the element to move to unlocked position; a key nose, the tumblers extending across the key nose to be displaced by operation of a key therein; spring means urging the tumblers toward the key nose Iand adapted to yield when the key moves them out; at Least sorne tunibleis having projections thereon engageable with the spring means prior to full movement of `such tumbilers by the key.

10. in a lock of the kind described: a housing, a pair oi key noses in the housing to receive keys to iactuate the lock; a locking element movable into locking and unlocking positions; at least one tumbler, means supporting the tumbler in the housing for movement to render the locking element movable, the tumbler lying adjacent both key noses, means including a key in each nose for displacing the tumbler through keying in the said nose; and means 1n the housing guiding the tumblers for such movement by keying, the .guide means being free of a fixed pivot for the tumbler. l1. In a lock: a housing, a bolt movable back Iand forth in the housing to unlocked and locking positions; at least one tumbler movably mounted in the housing adjacent the bolt; a key-receiving opening into the housing ,adjacent the tumbler; the tumbler liaving a islot and the bolt having fa lug that enters the slot when the bolt is moved to unlocked posiL'on, the entrance of the slot being approximately the size of the entering part oi the lug to require accurate positioning ot the tumbler to permit initial movement of the bolt, but the lug and slot being shaped -to prov ide lost motion when the bolt is in the unlocked position, to enable the tumbler to move if Ithe key is Withdrawn when the #bolt is unlocked. 1.2. The lock of claim ll, wherein the Islot is enlarged inside oit its entrance, and has its edge sloping toward the entrance to yaid in movement 'of the lug back toward the entrance during return movement of the bolt to locking position.

13. The lock of ldaim 11, wherein there isa key nose in the housing adjacent the key opening, the tumbler hein(y normally urged toward the key nose but beimY movable away from it by the key. o

141 The lock of claim 11, wherein there are two key openings .for .two keys, and the tumbler extends adjacent both key openings.

15. In a lock: a housing; first and second key holes in the housing in spaced relation to each other; a bolt mounted in thehousing for movement into locking and unlocking positions; a rigid, oating tumbler in the housing spanning .across both key holes, a tumbler supporting means adjacent each key hole to support the tumbler, the tumbler having a bolt-restraining portion that, when the tumbler is in the position adjacent both support means, obstructs movement of the bolt into unlocking position, which portion can be moved to a position wherein it does not obstruct the bolt; first tumbler-moving means. including a key inserted into the first key hole and operable by movement of the key for engaging the tumbler at a first point adjacent the first key hole, to move one end of the tumbler 'while its other end is held against the support means adjacent the other key hole; and second tumblermoving means including a key inserted into the second keyhole and operable by movement of the key for engaging the tumbler at a second point adjacent the second key hole, to move the secondend of the tumbler while its irst end is held against the irst tumbler moving means, both movements of the tumbler being required to dispose the bolt-restraining portion thereof in position where it does not restrain the bolt.

16. The lock of claim 15, wherein there are a plurality of such tumblers, movable to different distances by the first and second tumbler-moving means, to become disposed in bolt-releasing positions. y

17. The lock of claim l5, wherein the bolt-restraining portion of the tumbler comprises a head on one end beyond both keyholes, so that moving of the tumbler by the tumbler-moving means which is more remote from the head rocks the head downwardly and moving of the tumbler by the other and nearer moving means rocks the tumbler head upwardly.

18. The lock of claim 17 including a plurality of such tumblers, at least one, but not all, of which are disposed in bolt-releasing position upon being moved by only the more remote tumbler-moving means, and wherein the other tumbler-moving means contains no parts to move them.

19. `In a lock, a housing, a bolt in the housing having a lug, a tumbler movable in the housing to block and unblock the lug on the bolt, a key hole in the housing, the tumbler having an L-shaped edge facing the key hole, providing an edge over and above the key hole and eX- tending down and to one side thereof to provide a head at one side of the key hole, the head having a bolt-lug cutout to permit the bolt to be moved when the tumbler is moved to unlocking position; and a barrier in the housing at one side of the key hole and extending between the key hole and the side edge of the tumbler, to obstruct passage of a probe from the key hole across the head to detect the character of the bolt-lug recess.

20. The lock of lclaim 19, wherein the housing and the barrier form a pocket into which the tumbler heads are received, the bottom of the pocket being close enough to the bottoms of the tumbler heads to support the heads in bolt-lug blocking position if the heads are sawed oft adjacent the key hole.

2l. In a lock made up by selecting a tumbler out of a supply of such tumblers, all of which tumblers in the supply have operating portions to be acted upon by keyoperation of the lock, all of which have identical barriers to movement of a bolt and all of which have identical boltadmitting receptacles in predetermined position with respect to the barrier that are adapted to be moved the same amount by key-operation of the lock to position the boltadmitting receptacles at the saine place and all of which tumblers have basically the same general shape and maerial for resonance characteristics that are peculiar to all these tumblers having their bolt receptacles at the same place with respect to the barrier, the invention which comprises: a lock housing, a bolt movably mounted on the housing, a tumbler having the bolt barrier, bolt admitting receptacle, operating portion, and basic general shape and `qualities above-described, key-operated means engageable with the operating portion of the tumbler to move its bolt-admitting receptacle to position to receive the bolt and permit the bolt to be moved; and means to modify the resonance characteristics of the tumbler from others in the supply of otherwise identical tumblers, to prevent determination of the location of the bolt-admitting receptacle by obtaining a resonance pattern for this type of tumbler having this predetermined bolt-admitting re- 1 1 modifying means comprises recess means in the particular tumbler that distinguishes its resonance from others in the supply.

23. The lock of claim 21, wherein the resonance modifying means comprises a tumbler having diierent constituent material from `others in the supply.

24. The lock of claim 21, wherein there are a plurality of tumblers 'in the lock, each being taken from a supply, tumblers from one supply diiering from those of another supply by having a diierent position of the boltadmitting receptacles, and the individual tumbler of eac-h supply having means distinguishing its resonance characteristics from others of its supply.

References Cited in the file of this patent UNITED STATES PATENTS Himioben Feb. 20, Mosely Oct. 17, Varnum et al. Dec. 19, Eras June 1, Nichin Jan. 10, Drexler et al. Jan. 19, Doenges Oct. 8, Ellis Oct. 3, Morawitz Mar. 1, 

9. IN A LOCK: A HOUSING, A LOCKING ELEMENT MOVABLY MOUNTED IN THE HOUSING FOR DISPLACEMENT TO LOCK AND UNLOCK POSITIONS; AND KEY-OPERABLE MECHANISM TO CONTROL MOVEMENTS OF THE LOCKING ELEMENT FROM LOCK TO UNLOCK POSITION; THE MECHANISM INCLUDING A PLURALITY OF PRIMARY TUMBLERS IN THE HOUSING MOVABLE FROM RELEASED, LOCK POSITION TO UNLOCK POSITION; MOVABLY INTERENGAGEABLE ELEMENTS ON THE LOCKING ELEMENT AND ON THE TUMBLERS, THOSE ON THE TUMBLERS BEING DIFFERENTLY SPACED SO AS TO REQUIRE DIFFERENT AMOUNTS OF MOVEMENT FROM RELEASED, LOCK POSITION FOR DIFFERENT TUMBLERS TO ENABLE THE ELEMENT TO MOVE TO UNLOCKED POSITION; A KEY NOSE, THE TUMBLERS EXTENDING ACROSS THE KEY NOSE TO BE DISPLACED BY OPERATION OF A KEY THEREIN; SPRING MEANS URGING THE TUMBLERS TOWARD THE KEY NOSE AND ADAPTED TO YIELD WHEN THE KEY MOVES THEM OUT; AT LEAST SOME TUMBLERS HAVING PROJECTIONS THEREON ENGAGEABLE WITH THE SPRING MEANS PRIOR TO FULL MOVEMENT OF SUCH TUMBLERS BY THE KEY. 